This invention relates generally to security systems and is particularly directed to the programming of a plurality of remote sensors in a microprocessor-based security system.
Security systems are gaining ever increasing acceptance in a greater variety of environments. While initially limited to government and industrial installations, security systems can now commonly be found in the home. Regardless of the application or environment, the typical security system includes a master controller coupled and responsive to one or more sensors. The sensors may provide an intrusion alert, a fire alarm, movement detection information, or other information relating to the environment being monitored. The remote sensors may be either hard wired to the controller or may be coupled to the controller via an RF link. Other approaches may make use of ultrasonic or infrared signals transmitted from the sensor to the controller. The controller may either provide an alert signal at the location being monitored or may be coupled to a remote central station, such as a police or fire station. Sensor information received by the controller may be provided to the central station via an RF link or a conventional telephone line. It has also been proposed to integrate the security system with a cable television (CATV) network, wherein the distribution cable is used to transmit CATV programming as well as security system status information.
Due to the widespread availability and acceptance of home security systems, the unique identification of sensors as well as controllers in each individual security system is necessary. For example, where RF links are used in neighboring houses to convey remote sensor information to a respective controller in each of the houses with a common frequency used by both systems as is generally the case, each of the sensors as well as each set of sensors in each of the houses must be assigned a unique identifier to enable each controller to not only respond to only those sensors which form part of its security system, but also to permit the controller to identify and distinguish between each individual sensor within its system.
Prior art multi-sensor security systems having a common controller generally make use of dual-inline-packaged (DIP) switches for assigning each remote sensor and controller a unique identifying address. This addressing arrangement represents a binary approach wherein each individual switch is either set or not set and corresponds to either a 1 or a 0 in a multi-bit address byte. This approach further requires the programmer, typically a home owner installing the system, to set the correct binary code in each sensor which uniquely identifies that sensor and in the controller which enables it to respond to only those sensors with which it is associated and to ignore RF signals emanating from remote sensors within other home security systems.
The setting of linear arrays of DIP switches, while perhaps routine to the technician skilled in the art, is frequently beyond the capability of the typical layman unfamiliar with electronic switching and coding arrangements. In addition, the DIP switches, which may number as many as 16 in a linear array, are not susceptible to miniaturization and thus limit the extent to which sensor size may be reduced. This is a critical consideration where it is desirable to minimize sensor size in reducing the possibility of sensor detection which is generally the case in most security systems. Finally, in addition to the relatively high cost of these DIP switches, the prior art approach requires each remote sensor as well as the controller to be individually programmed with a unique address which further complicates and increases the time required for initial sensor system set-up and also makes re-programming of the various security system components more difficult when it is necessary to change component identifier addresses.
The present invention overcomes the aforementioned limitations of the prior art by providing a microprocessorbased remote security transmitter address programmer which is responsive to user-initiated keyboard entries for simultaneously programming a security system controller and a sensor coupled thereto with addresses for uniquely identifying the controller as well as a plurality of such remote sensors which comprise the security system. The address programmer arrangement of the present invention allows for a reduction in remote sensor size and cost, simplifies the address programming procedure to permit even the unskilled to easily encode security system components, and enhances the reliability of the security system.